Motor-controller.



G. R. RADLBY.

MOTOR CONTROLLER.

APPLICATION FILED OUT. 2, 1911.

Patented Dec. 8, 1914.

M ,Z V m 4 ise/ 1 UNITED sTATEsPArEN OFFICE.

GUY R. RADLEY, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAMMERMFG. (30., OF MILWAUKEE, WISCONSIN, A. CORPORATION WISCONSIN.

MOTOR-CONTROLLER.

To allwlmmv't may concern:

Be it known that I, GUY R. HADLEY, a

citizen of the United States, residing at Milwaukee, in the county ofMilwaukee and .State of Wisconsin, have invented new and usefulImprovements in lVlotor-Gontrollers, of which the following is a full,clear, concise, and exact description, reference being had to theaccompanying drawing, forming a part of this specification.

My invention relates to a method and means for controlling electricmotors.

It is one of the objects of my invention to provide a method and meansfor connecting the field windings of an electric motor either in seriesor parallel relation and to accomplish the transition from one relationto the otherwithout interruption of the motor circuit and withoutexcluding either field winding therefrom.

Various other objects and advantages of my invention will be hereinafterclearly and i fully set forth.

For the purpose of clearly and fully setting for'th the nature andcharacteristic features of my invention, I shall describe the controllerdiagrammatically illustrated in the accompanying drawing which embodiesmy invention in its preferred form. It should be understood however,that my invention is not limited to the specific embodiment thereofillustrated.

In the accompanying draw1ngs:F1gure 1 is a. diagrammatic view of thecontroller and Figs. 2, 3, 4 and 5 are diagrammatic views showing thedifferent circuit connections established by movement of the controllerillustrated in Fig. 1 to different positions. v

The controller selected fort-he purpose of illustration is particularlyapplicable tothe control of electrically operated vehicles, but might ofcourse be used for various other purposes The motor illustrated includesan armature A and two series field windings F and F. The motor issupplied with current from a storage battery S B through a suitablecontroller C hereinafter fully and clearly described. Ilesistanc'es Rand R are also provided for a purpose hereinafter set forth.

As above set forth it is one of the objects of my invention to changethe relation. of

the field windings from series to parallel or Specification of LettersPatent.

'nals of the resistances.

Patented Dec. 8, 1914. Serial No. 652,407.

vice versa without interrupting the motor circuit and without excludingeither field winding therefrom. The controller illustrated willreadily'accomplish this object, but before describing the same, I shallbriefly set forth my preferred method of accomplishing the object.

According to my preferred method I first connect the armature A,'seriesfield windings F and F and resistances R and R all in series across theterminals of the storage battery. The motor will thus operate as anordinary series motor both field windings being connected in series. Theresistances It and R are used under these conditions for limiting thefiow of current in the motor circuit for the well-known purpose.

After establishing the connections j ustde scribed I establish a directconnection from one field winding to the other to short circuit theresistances R and It. At the same connection between the right handtermi- Fig. 3 shows the connections thus obtained. Under theseconditions the field windings remain in series, but with the resistancesexcluded, thereby permitting a greater flow of current in the motorcircuit and in consequence increasing the speed of the motor. Of coursein practice the resistances need not be included in the motor circuit upto this time if not desired. I then make the cross connections shown inFig. 4, at the same time maintaining the connections shown in'Fig. 3.The cross connections briefly described connect the right hand terminalof resistance It with the left hand terminal of field winding F and theright hand terminal of resistance R with the left hand terminal of thefield winding F. Under these conditions the field windings remain inseries but with one section of resistance in parallel with each windingand in series with the other winding. This increases the speed of themotor.

To secure the parallel relation of the field windings, I first interruptthe directconnection between the field windings as shown in diagram AFig. 5, thereby interrupting the series connection between the fieldwindings. This leaves the field windings in parallel with a resistancein series with each. I then immediately exclude these resistances fromcircuit obtaining an increased speed through the parallel connection ofthe windings.

The change fromparallel to series relation is accomplished in just thereverse order to that above described. It will thus be seen that theabove described method provides for readily changing the field windingsfrom series to parallel relation or from parallel to series relationwithout interrupting the motor circuit and further without disconnectingeither field winding from circuit or short circuiting either fieldwinding. It will further be observed that the foregoing method providesfor a very gradual change in the electrical conditions of the motorcircuit through the medium of the resistances which are cut in and outand changed from series to parallel relation or vice versa as thesuccessive changes in the motor circuit are made. This fully protectsthe motor against electrical shocks and in consequence protects thedriven mechanism against mechanical shocks.

- I shall now describe the controller illus trated in Fig. 1. Thiscontroller is shown schematically as provided with two sections I andII. The section I is movable independently of the section II- forestablishing charging connections and for connectingone of the contactsof section II of the controller to the battery for running. The sectionII of the controller is adapted to be moved to different positions toestablish the motor connections heretofore described.

The section I of the controller comprises stationary contact fingers 3and 4 and contact segments 3 and P adapted to engage said contactfingers 3 and 4 respectively. It may be assumed that the contactsegments 3* and 4 are mounted upon a movable drum having threepositions, to-wit a central off position in which position the segments3 and 4 are out of contact with their respective fingers, a chargingpositlon in which the contact segment 8 engages contact fin-,

ger 3 and a running-position in'which segment 49 engages finger 4. Thefinger 3 is connected to one side of a charging circuit.

5, while the segment 3 is connected by a flexible lead 6 to one terminalof the storage battery. Thus assuming the section I of the controller tobe in the charging position.

current would flow from the positive line of the charging circuit to thepositive side of the battery, through the battery by conductor 6,segment 3 andfinger 3 to the negativesideof the charging circuit. In thecharging circuit I have schematically illustrated an ampere hour meter 7which is also common to the discharging circuit. Of course in practiceany preferred measuring instruments may be connected in the twocircuits. The contact segments 3 and 4 are electrically connected whilethe contact finger 4 is connected to a contact of section II of thecontroller. Hence when section I of the controller, is in runningposition, circuit will be closed from the negative side of the storagebattery to the controller II.

The controller II comprises a series of stationary contacts 8, 9, 10,11, 12 and 13. 'lhuso contacts are adapted to be engaged by two sets ofcontact segments which it may be assumed are mounted upon a drum adaptedto be moved in opposite directions from a central oil position to bringeither set of segments into engagement with said contacts. It may.further be assumed that the drum has four positions in one directionwhich we will term forward and two po- Sitions in the opposite directionwhich we will term reverse. The forward contact segments includesegments 8 and 9, adapted to engage contacts 8 and 9 in all forwardpositions of the controller; a segment 10 adapted to engage contact 10in the fourth forward position; segments ll and 11, the former to engagecontact 11 in the second and third forward position, and the latter toengage contact 11 in the fourth forward position; segments 12 and 12",the former adapted to engage'contact 12 in the first forward positionand the latter to engage contact '12 in the third forward position; asegclearly and fully setting forth the circuit connections therefor.

For the purpose of this description let it be assumed that the section Iof the controller is in running position and that section II of thecontroller is moved to the first forward position. (lircuit willthereupon be established from the positive side of the storage batteryby conductor 15 through the ampere hour meter 7 by conductor 16 throughthe series field winding F and resistance R, flexible conductor 17tosegment 13 of the controller by conductor 18 to segment 12 contact 12resistance 'R, series field winding F, conductor 19, contact 9, contactsegment 9*,

flexible conductor 2-0 through the motor armature,flexible conductor 21to segment 8. contact 8, contact 4 of the controller, section I, segment4 to segment -3 by conductor 6 to the negative. side of the storagebattery. This completes the motor circuit as illustrated in Fig. 2before described in which the motor armature, both field windings andboth resistances are connected in series across the terminalsof-the'storage battery.

- tions of Fig. l before referred to.

Assuming now that the controller be saidshort circuit extending from apoint between field winding F and resistance R by flexible conductor 22to segment 10 by conductor 23 to segment 11*, contact 11 ;to a pointbetween field winding F and resistance R. .Also by virtue of the contact12 disengaging the contact 12 the connection between the lower terminalsof the resistance sections R and R will be interrupted. This position ofthe controller accordinglygives the circuit connections shown in Fig. 3.

Assuming now that ,the' controller be moved to the third forwardposition, the following additional circuitswill be completed: first,from the lower terminal of resistance R by conductor 1'? to segment 13?,contact 13, conductor 25, contact 10 to the upper terminal of seriesfield winding F. This establishes one of the cross'connec- The othercross connectionis established from the upper terminal of the fieldwinding F by flexible conductor 26, segment 11 by conductor 27 tosegment 12*, .contact 12, to the lower terminal of resistance ll. Aswill be seen from the drawing the seg ment 11 which completes the directconnection between the field windings overlaps the segment 12*, and inconsequence maintains the circuit connections shown in Fig. 3. Thus thisposition of the controller gives the connections shown in Fig. l.

During movement of the controller to the fourth position segment 11leaves contact 11, thereby interrupting the series connection betweenthe field windings. This gives the circuit connections shown in diagramA Fig. 5. Also during movement to the fourth position segments 12 and 13leave contacts 12 and 13 and contacts 10 and 11 engage contacts 10 and11 respectively. This results in connecting the lower terminal of fieldF by conductor 22, segment 10 to contact 10 and accordingly to the upperterminal offield winding F and also in connecting the upper terminal offield winding F by conductor 26, segment 11, contact 11 to the lowerterminal of field F. Thus the two field windings are connected inparallel with the resistances R and R excluded from circuit, giving theconnections shown in diagram B Fi 5. It will thus be seen that movement0 the controller in the forward direction fully cari'ies out the methodheretofore described, establishing all of the connections desired.

the motorto operate in the opposite direc-v tion. When moved to thesecond reverse position the controller makes the same changes inconnections that it makes in the secondforward position, that is'to sayit short circuits the resistances R and R. No

provision is made for changing the field connections upon the reversemovement of the controller, as such changes are ordinanly entirelyunnecessary. It should be understood however, that the reverse side ofthecontroller might be made an exact duplicate of the forward side andthus produce all of the variations heretofore described if desired.

While I have shown numerous of the segments connected by conductors, itshould be nnderstood that all or any number of the segments might bemounted upon a conduct ing frame so that no special connections would berequired.

ll claim as new and desire to secure by Letters Patent is v l. Themethod of changing the relation of motor field windings from series toparallel consisting in. establishing parallel connections for the fieldwindings prior to interruption of the series connection, placingresistances in said parallel connections to prevent short circuiting ofeither field winding and then interrupting the series connection of thefield windings.

2. The method of changing the relation of motor field windings fromseries to parallel, consisting in connecting a resistance.

in series with each winding and in parallel with the other winding whilesaid windings remain connected in series and then interrupting theseries connection.

3. The method of changing the relation of motor field windings fromseries to par and relation or vice versa consisting in providing both aseries connection and a parallel connection including a resistance inseries with each winding and in parallel with the otherwinding prior tothe change in relation of the windings and then interrupting eitherseries or parallel connections to give the desired relation of the fieldwindings.

4. In combination, an electric motor having a plurality of fieldwindings and a,

series-parallel controller therefor including resistances and meansoperable for connecting each of said resistances in series with one ofsaid windings and in parallel with another of. said windings while theseries connection of said windings is maintained and subsequentlyinterrupting the series connection of said windin s.

5. In combination, an e ectric motor provided with a plurality of fieldwindings, means for connecting said field windings in either series orparallel relation without interruption of the'motor circuit andresistances connected in circuit by said means to preventshort-circuiting of either of said said contact fingers having threeconnections to the terminals of theother of said field windings and itscorresponding resistance, and two of said contact fingers beingelectrically connected, whereby said segments and fingers may be engagedto establish either series or parallel connections for said fieldwindings.

In witness whereof, I have hereunto subscribed my name in the presenceof two wit-. 25

nesses.

GUY R. HADLEY.

Witnesses:

FRANK I-I. HUBBARD, GEO. DAYNIE.

